Electric circuit controller



Sept. 8, 1953 w. R. GRACEY, JR

ELECTRIC CIRCUIT CONTROLLER 5 Sheets-Sheet 1 Filed Dec. 27, 1948 Hfs ,arf/own I Sept. 8, 1953 w. R. GRAcEY, JR l 2,651,698

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ELECTRIC CIRCUIT CONTROLLER 5 Sheets-Sheet 4 alma Nrl P. EJ? y 0e I w ww E wip w W r vw A s .m m W Filed Dec. 27, 1948 Sept. 8, 1953 w. R. GRACEY, .1R

ELECTRIC CIRCUIT CONTROLLER Filed Deo. 27, 194B 5 Sheets-Sheet 5 HA'S' TTHVE'Y Patented Sept. 8, 1953 ELECTRIC CIRCUIT CONTROLLER William R. Gracey,

ration of Pennsylvania Application December 27, 1948, Serial No. 67,264

8 Claims.

My invention relates to an electric circuit controller, and particularly to a controller for shunting a track circuit and for controlling other circuits in a railway signal or control system.

It is sometimes necessary or convenient to provide a manually operable track switch in a section of a railway in which the signals are automatically controlled. In order to protect trains approaching such a switch, it isdesirable to prevent manual operation of the switch until the signals have been set to stop for an adequate warning period. This may be done by providing a switch lock controlled by a manually movable member and a timer. The manual member may be operated at any time to set the signals governing the track approaching the switch to display a stop aspect, and start the timing mechanism running. -After a predetermined time has expired, the timing mechanism releases the lock to permit manual actuation of the track switch.

The copending application for Letters Patent of the United States, Serial No. 749,833, of Howard A. Thompson, filed May 22, 1947, now Patent 2,539,937 issued January 30, 1951, for Trafc Protection Apparatus, illustrates a switch locking system of this type. Thompson shows a track switch operable by means of an electrically locked handthrow lever, and a circuit controller operated by an auxiliary lever movable between normal and reverse positions. When this auxiliary lever is first moved away from its normal position, the circuit controller shunts the track circuit, thereby setting the signals governing trains approaching the switch to stop. As the motion of the manual auxiliary lever to its reverse position is completed, it actuates additional contacts to initiate the operation of a timing mechanism which eventually releases the electric lock on the handthrow lever of the track switch.

The present invention relates to a circuit controller for use in a system of the type described in the Thompson application.

An electric circuit controller for shunting a railway track circuit and for controlling additional circuits, if mounted on the railway ties, is subject to severe conditions of vibration. This vibration will cause undue wear between the parts if relative motion of the parts is not prevented.

Where such a controller is used to shunt a track circuit on an electric railway, it must have high current carrying capacity. On electried railways, the rails are commonly used as a current flow path, and unbalanced resistance conditions in the opposite rails may cause high current flow through track shunting contacts. Such a controller must therefore have heavy duty contacts. Ii? the controller is required to additional- Jr., Swissvale, Pa., assignor to Westinghouse Air Brake Company,

a corpo- (Cl. 20G-163) 2 ly control other circuits, for example signal or control circuits, then additional light duty contacts must be provided in the controller.

Where a controller is to be mounted on the ties of a railway, it is desirable that its overall height be low enough so that it may be mounted between the rails of a track without projecting sumciently above the track to foul any portion of the equipment passing over it.

An object of my invention is therefore to provide an improved electric circuit controller of high current carrying capacity.

IAnother object is to provide an electrical circuit controller which may be subjected to severe vibration without producing undue wear between the moving parts of the controller.

A further object is to provide an improved controller including a set of heavy duty contacts and a set of light duty contacts in the same casing and operated by movement of the same control member.

A further object is to provide an improved controller of the type described in a compact structure so arranged that it may be mounted between the rails of a railway track without projecting far enough above the track rails to foul rolling stock passing over it.

According to my invention, I achieve these objects by using elongated xed and movable contacts mounted horizontally, and support the movable contact so that it is moved horizontally to open and close the circuit. This construction aids in keeping the overall height of my controller at a minimum. In order to provide high current carrying capacity, one of the contacts is made in lthe form of a flat bar having convex upper and lower surfaces. This bar moves between a pair of flat spring contacts which, in their disengaged condition, are spaced apart by a distance somewhat less than the distance between the opposite convex surfaces on the bar contacts. In this way, a line contact is maintained between the bar and the flat springs.

The controller is operated by an external manual lever which rotates a shaft through an angle of This shaft is connected to the movable contact supporting structure through a crank and pitman to provide a linear movement of the movable contact upon rotation of the shaft.

The movable contact is loosely mounted on its support so that minor misalignments between the xed and movable contacts may be accommodated. The spring contact structure is eiective when the contacts are closed to take up all lost motion in the contact support operating mechanism, so as to prevent wear in the operating parts due to vibration. A stationarily supported spring is provided in the path of move- :nent of the movable contacts so as to engage those contacts as soon as they separate from the stationary contact. This spring device places the movable contact and the contact operating element under tension, and thereby is effective when the contacts are open to take up all lost motion in either the loose mounting of the movable Contact or in the bearings of the shaft, crank, and pitman.

The light duty contact assembly is mounted on a bridge structure above the pitman and is perated by a cam adjustably xed on the crank shaft.

@ther objects and advantages of my invention will become apparent as the description proceeds.

I shall describe two forms of circuit controllers embodying my invention, and shall then point out the novel features thereof in claims.

In the drawings, Fig. l is a cross-sectional view of one form of electric circuit controller constructed in accordance with my invention, taken along the line I-I or Figs. 2 and 3, looking in the direction of the arrows. Fig. 2 is a plan view of the controller of Fig. l, with the cover removed. Fig. 3 is an elevational view of the left-hand end of the controller of Figs. 1 and 2. Fig. l is a plan view of a railway track layout showing certain railway trailic control apparatus, including a circuit controller built according to Figs. l3, mounted between the rails. Fig. 5 is an elevational view of the control apparatus of Fig. e. Fig. 6 is a cross-sectional View of a modiiied form of controller built in accordance with my invention. Fig. 7 is a plan view of the controller of Fig. 6 with the cover removed. Fig. 8 is a detail cross-sectional View taken along the line VIII-VIII of Fig. '7. Fig. 9 is a plan view similar to Fig. 4 illustrating the mounting of railway traffic control apparatus including a circuit controller built according to Figs. 6 and 7. Fig. l0 is an elevational View of the control apparatus of Fig. 9.

Figs. 1 to 3 Referring to the drawings, there is shown in Figs. l to 3 a controller generally indicated at i. The controller l includes a casing 2 having mounting feet 3 and a removable cover li. A latch of known construction, is provided to hold the cover in place. A squared shaft e projects outside the casing and carries an operating lever l having a handle 8.

One end of the casing i is open, and is closed by means of an insulating plate 9 attached to the casing by means of bolts lil. Four contact supporting blocks li, i2, i3, and ill (see Fig. 3) are attached to the insulating plate 9 by means of bolts iii. The blocks il, i2, i3, and lli carry electrical terminals iii, il, i8, and i9, respectively, which extend outwardly through the insulating plate El. The outside ends of these terminals are adapted for the attachment of suitable heavy current conductors for shunting the rails of a track circuit. Inside the casing 4, each of the contact supporting blocks carries a pair of spaced spring contact blades 2li. These blades 2li are elongated in the horizontal plane and are slotted, as at Zta, to permit independent movement of the portions between the slots, so as to accommodate misalignment of the contacts.

It should be noted that the blades on the upper contact supporting blocks il and i2 are horizontally aligned with each other and that the blades 2@ on the lower contact supporting 4 blocks it and if?, are likewise horizontally aligned with each other. The upper set of blades 20 is adapted to be bridged by a movable contact bar 2l, and the lower set of blades 29 may be bridged by a movable contact bar 22.

The bars 2i and 22 are formed with relatively narrow edge portions 2id, 2lb, 22a, and 22h and wider central portions tic and 22C having convex surfaces. The convex surfaces 2lc and 22C are made wider than the distance between the spring blades 2&3, so that when the Contact bars Ei and 22 move between the blades 2D, those blades ride on the convex surfaces, thereby producing substantially a line contact between the blades and the contact bars.

The advantage of a line contact is that it provides high current carrying capacity while the force necessary to operate the movable contacts is held at a minimum. This advantage is gained by arranging the parts to produce high contact pressures so that correspondingh7 high current densities may be used.

A line contact could alternatively be obtained through the use of a iiat bar contact and a contoured spring contact. The construction shown is greatly to be preferred, however, since it is much easier to maintain accurate dimensions in a solid bar with a convex contour than it is in a relatively thin flexible spring with a corresponding contour. rThe dimensions of the bar and spring contacts are very important in this construction, because these dimensions are major factors in determining the contact pressure and hence the allowable current density.

The opposite ends of the c-ontact bars 2l and S2 are loosely received in recesses 25S formed in a pair ci movable contact supporting slide blocks 2li, of insulating material, Each of the slide blocks 2d moves between a lower guiding surface formed in the casing 2 and an upper guiding surface 2t formed on the lower side of a rail 21 attached to the side of casing 2 by means of bolts 28.

The slide blocks 24 are connected by means of a crosshead rod 29, which is in turn connected by two pitmans 30 to crank arms 3l attached to the shaft ii. Each pitman 30 is connected to its associated crank arm 3l by means of a pin 32. Each pitman 3@ is curved, as indicated at 30a in Fig. 1 to permit rotation of the shaft 6 further in a counterclockwise direction (as viewed in Fig. l) than would otherwise be possible. The crank arms 3l are rigidly attached to the shaft 6 by any suitable means, as for example by using a split crank arm as indicated at Bla, and a bolt Sib to tighten the opposite parts of the crank arm together.

At all bearings, such as the bearings of shaft the pins 32, and the crosshead rod 29, a certain small clearance must be allowed so that the relatively rotatable members can turn freely and without binding. A controller intended to be mounted on a railway track is likely to be subjected to very severe conditions of vibration. The vibration tends to cause the relatively rotatable parts to move relative to each other, because of the clearances between them, thereby causing friction and wear of the parts. Also, the vibration might cause movement and wear of the contact bars 2l and 22 in their sockets 23 unless some means is provided to prevent it.

I prevent wear due to such vibration conditions by the provision of two springs 33 mounted on a bracket 34 so that they are aligned with the contact bars 2l and 22. The bracket 34 is attached as by bolts-35 to the bottom of the casing 4. The springs 33 are so arranged that as the contact bars 2| and 22 move to their normal open circuit position, as shown in the drawings, they engage the springs 33. The springs 33 thereby hold the contact bars 2| and 22 tightly against the left-hand ends of their supporting recesses 23, as viewed in Fig. 1 At the same time, the springs 33 place all the bearings associated with the pitman 30, crank 3|, and shaft 6 under tension, so that all lost motion due to clearances between these parts is taken up. Since the parts are held rmly against each other, they cannot rub or pound so as to cause excessive wear.

The stationary contact assembly, including the mounting plate 9, the contact supporting blocks I2, I3, and |4, the connectors I6, I1, I8, and I9, and the contact blades 20 is removable as a unit from the casing by taking out the attaching bolts I0.

The light duty contacts of my controller are mounted on a pair of supports 36 which are removably attached to the bottom of the casing adjacent the opposite sides thereof. An in'- sulating plate 31 is attached to the tops of the supports 36, and bridges the pitmans 30. The plate 31 carries a row of fixed contacts 38, and a row of movable contacts 39, all of the leaf spring type. The movable contacts 39 are longer than the fixed contacts 38, and their ends project into suitable notches 49 formed in an insulating member 4|. The member 4| is carried by a yoke 42, whose ends are pivotally attached to a shaft 43 journaled in the supports 36.

The insulating member 4| is carried on a cross bar 42a of yoke 42. At the ends of the cross bar 42a the yoke is provided with bolts 44 which engage hubs 45 formed in the casing 2, in which hubs the shaft 6 turns. A pair of biasing springs 46 have their upper ends connected to the yoke 42 and their lower ends connected to brackets 41, which are attached to the casing 2 by certain of the bolts which hold the supports 36. The biasing springs 46 hold the yoke 42 down so that screws 44 engage the hubs 45. The insulating support 4| is then in the path of movement of an adjustable cam 48 mounted on the shaft 6. With this construction, the entire light duty contact assembly including supports 36, plate 31, contacts 38-39, yoke 42, and springs 46 may be removed as a unit for inspection or repair without disturbing the heavy duty contacts or their operating mechanism.

Cam 48 comprises an operating portion 48a and a clamping portion 48h secured together by means of an adjusting screw 48e and a clamping bolt 48d. The adjusting screw 48e cooperates intermediate its ends with an annular threaded groove 49 formed in the shaft 6 in such manner that by first backing olf the clamping bolt 48d and then rotating the adjusting screw 48e the cam can be readily rotated to any desired angular position relative to the shaft. After the desired adjustment has been made, the clamping bolt is again tightened and the cam will then be securely held in its adjusted position.

The lower end of insulator 4| lies in the path of the operating surface of cam 48. When cam 48 engages the insulator 4I, it moves upwardly, carrying with it the movable contacts 39 into engagement with their associated stationary contacts 38.

By means of adjustable cam 48, any desired relationship mayV be established between the angular position of shaft 6 at which the heavy duty contacts are operated and the angular position of shaft 6 at which the light duty contacts are operated. For example, where the heavy duty contacts are used to shunt a track circuit, then it is desired to have the light duty contacts set so that their circuit is not completed until the motion of the hand operating lever 1 to its reverse position is substantially complete. rThis mode of operation will be secured with the cam adjusted as shown in the drawings. With the cam in this position, the light duty contacts are not operated until the shoulder 48e of the cam moves around and engages the insulator 4|.

The insulating block 31 is provided with suitable terminals 58 connected to each of the contacts 38 and 39. The casing is provided with conduit outlets 5I for permitting the passage of wires leading to the terminals.

It may be seen that upon clockwise rotation of the shaft 6 by the manual lever 1, the contact bars 2| and 22 will be moved to the left to engage their respective stationary contact blades 20. After this engagement has been made, the cam 48 will thereafter operate the light duty contacts 38 and 39 to their closed positions.

Both the Xed and movable heavy duty contacts are elongated horizontally to obtain the required size and current carrying capacity. This construction of the contacts and the mounting of the movable contacts for horizontal movement allow my circuit controller to be constructed with a low overall height so that it may be readily mounted between the rails of a railway track.

Figs 4 and 5 There is shown in these gures railway traffic controlling apparatus including an electric circuit controller I of the type described in detail in connection with Figs. 1 to 3. This apparatus illustrates one manner in which that circuit controller may be utilized in practice. There is shown a portion o-f a crossover track between two main tracks, including rails 52 and 53 supported on ties 54. The switches at the opposite ends of the crossover track (not shown) may be provided with any suitable manually operable switch stands for moving the switches between their normal and reverse positions. These switches are locked in their normal position by means of locking mechanisms of the type illustrated in Letters Patent of the United States No. 1,654,023, issued December 27, 1927, to C. C. Thorn. The locking mechanisms for both switches are controlled simultaneously by a pipe line 55 extending between the switch stands. When the pipe line 55 is in the position shown in the drawings, both switches are locked, and it is shiftable endwise from that position to unlock both switches simultaneously. The pipe line 55 may be shifted by means of an adjustable link 56 connected between a point on the pipe line and a crank pin 51 carried by a crank arm 58 on a crankshaft 59 supported by a center throw lever stand 58. The crankshaft 53 also carries a hand-throw lever 5| by which the shaft 59 and crank 58 may be rotated. The handthrow lever 6I is locked in the position shown in the drawings by means of an electric lock generally indicated at 52, which is preferably of the type shown and claimed in the copending application for Letters Patent of the United States, Serial No. 67,392, of Herbert L. Bone, entitled Railway Trailic Controlling Apparatus, led December 27, 1948, now Patent No 2,631,228 issued March 10, 1953.

For the purposes of the present application, it is believed sufficient to state that the lock 62 includes a latch 53 operated by a pedal 64. The latch 63 and pedal Ell are held in the position shown in the drawings by an internal electric locking mechanism, in which position the latch 63 extends over the hand-throw lever 6| and holds it down.

The lock B2 and the center throw lever stand 69 are mounted on a plate 65 attached to the ties 5d.

When the electric lock 62 is deenergized, the pedal 5H. is locked so that latch 63 cannot be released. When the electric lock 62 is energized, the pedal bmay be depressed to release latch 63.

In the constructio-n shown in the drawings, downward movement of the foot pedal 64 is further prevented by a bolt 66 which moves in guides 6l attached to the plate 65. In the position shown, the bolt 6% lies immediately under the pedal @il and prevents its downward movement. The opposite end of bolt B6 is connected through an ladjustable link 68 to a pin 69 which passes through an eccentric hub 10 formed in the hand-throw lever 'i of the circuit controller l.

The hand-throw lever 6I is provided with the usual lever lock rod ll, which cooperates with the pedal Sli to prevent restoration of the latch t3 to its latching position while the hand-throw lever 6l is away from its normal position.

As previously mentioned, the heavy duty contacts in the electric circuit controller l are effective when the hand-throw lever 'l is reversed from the position shown to shunt the track circuits, and thereby set the signals associated with the main line tracks at stop. At the same time, the light duty contacts of the circuit controller l are effective to initiate operation of a timing mechanism which causes the electric lock 62 to be energized after a predetermined period of time. Operation of the hand-throw lever l from the normal position shown in the drawing to the reverse position 180 away from the normal position is also effective to move the bolt 66 out from under the pedal iid of the electricl lock 62, so that as soon as the predetermined time has expired, the pedal may be depressed to release the hand-throw lever E5 I. As soon as the hand-thro-w lever Si is operated, the locks on both the switches are released and the switches may be thrown so that the crossover track may be used.

When it is desired to restore the crossover track to its normal operating condition, botlh switches are first restored to their normal positions, and the hand-throw lever 6l of the locking mechanism is then restored to normal. The pedal and latch @3 are restored to their latching positions, and then the hand-throw lever 1 of the circuit controller i may be restored to its normal position. It should be noted that the bolt 66 interlocks the circuit controller l with the electric lock 62 so that the circuit controller lever l cannot be restored to its normal position until the pedal ed is returned to its normal lever latching position.

Figs. 6 to 8 There is shown in these gures another form of electric circuit controller, generally indicated by the reference character l2, which is adapted for use in an installation to be described hereinafter and which includes a modified form of heavy duty contact mechanism.

The circuit controller l2 includes a casing 13 having a cover 14. Near the left end of casing 13, as it appears in the drawings, a shaft 15 extends transversely through the casing and outwardly beyond both sides of the casing. On one end of the shaft 15 is fixed a hand-throw lever 'I6 and on the opposite end of the shaft l5 is fixed a crank arm l1.

A circuit controller operating shaft 'i8 also extends through the casing transversely and has one end projecting outside the casing and carrying a hand operating lever 19.

Inside the casing '53, the shaft E8 is arranged to operate a set of heavy duty contacts and a set of light duty contacts. The mechanism for operating the heavy duty contacts includes a pair of crank arms E@ iiXed on the shaft 'I8 by suitable means and connected by crank pins 8i to a pair of pitmans 82.

The pitmans 82 are provided with lateral curves 82e to permit rotation of the crankshaft T9 farther in a counterclockwise direction without fouling the shaft than would otherwise be the case. The opposite ends of the pitrnans S2 are pvotally connected toa crosshead rod 33 journaled at its ends in a pair of slide blocks Eli. Each of the slide blocks dll moves between a lower guiding surface dii cast integrally with the casing "f3 and an upper guide rail E6 bolted to the side of the casing i3.

The slide blocks 8d support the opposite ends of an insulating plate 8l, which carries the movable contacts of the heavy duty circuit controller. These slide blocks Sli are provided with apertures 84a, which loosely receive projections Sla, on the ends of the insulating plate 8l, so that the latter is loosely mounted at its ends in the slide blocks e4.

Mounted on the insulating plate 3l' are two sets of heavy duty contacts, the sets being generally indicated respectively by the reference characters S8 and 89. Each set comprises two channel-shaped spring members 39 and Si (see Fig. 6) of different widths. These channelshaped members are held together in nested relation on the insulating plate Si by means of bolts 92. The spring members 9B and 9i are slotted, as shown at a. in Fig. 7, so as to accommodate misalignment of the contacts.

Each set of movable heavy duty contacts 88 andl cooperates with a pair of upper and lower stationary Contact bars 93 and 96. The contact bars 93 and 9d are mounted by means of bolts 95 on an insulating terminal board 96 which closes an open end of the casing is. rlhe contact bars 93 and Srl are provided with integral extensions 93a and Ma which pass through the insulating board 95 and are provided outside the casing i3 with terminal lugs ill.

The contact bars 93 and 911 are provided with. relatively thin edge portions 93a and Sila narrev/er than the space between the spring contact members 99 and 9i, and relatively thick central portions having convex surfaces 93h and 94h. These convex surfaces are made wider than the distance between the spring blades 99 and 9|, so that when the blades engage the contact bars, a line contact is produced.

A spring loading mechanism is provided for the heavy duty movable Contact structure to prevent rattling and wear due tovibration. This mechanism includes a U-shaped bracket 98 mounted on the bottom of the casing '53. rIwo spring rods 99 extend through apertures in the opposite sides of the bracket 98. Each spring rod 99 carries a spring retaining washer lill).

A spring |0| encircles each spring rod between the left side of the U-shaped bracket 98 and the spring retaining washer |08. rIhe springs bias the spring rods 99 to a position in which the washers |69 engage the inner surface of the right-hand side of the U-shaped bracket 98. When the movable heavy duty contact structure is in its normal position, as shown, the insulating plate 81 is moved against the ends of the spring rods 99 so as to compress the springs |U|. The springs are thereby effective to take up all lost motion between the plate 8l and the slide blocks 84, and are also effective to take up the lost motion in the bearings of the mechanism which drives the slide blocks 84. l

The light duty contact structure of my controller is mounted on a pair of supports H32 which are attached to the bottom of the casing 13 adjacent the opposite sides thereof by means of bolts |03. An insulating plate |64 is mounted on the supports H32, spanning the pitmans 82. The plate |04 carries a row of fixed contacts |05 and a row of movable contacts IBG, all of the leaf spring type. rlhe movable contacts |06 are longer than the fixed contacts |65, and their ends project into suitable notches formed in an insulating member G1. The member |01 is carried by a yoke |58, whose ends are pivotally mounted on pins |99 set in the supports |92. The yoke IGS has a crossbar ia which carries the insulating member 4l. The lower edge of crossbar lSa is contoured to provide a cam follower which cooperates with a cam |I|1 attached to the shaft 18. A spring |9822, connected between yoke |08 and a bracket |08c held in place by one of the bolts |03, biases the follower into engagement with cam As in the case of the controller of Figs. 1-3, the entire light duty contact assembly may be removed for inspection or repair without disturbing the heavy duty contacts.

Cam HG (see Fig. 8) comprises two portions Illia and ||b secured together on the shaft 18 by means of a clamping bolt lli. An adjusting screw H2 passes freely through openings in the cam portions ||Ba and Hilo and is held against longitudinal movement with respect to those cam portions by its head and by a lock nut H3, respectively. The adjusting screw l2 cooperates intermediate its ends with an annular threaded groove 18d formed in the shaft '18. By loosening the clamping bolt and rotating the adjusting screw H2, the cam may be readily moved to any desired angular position relative to the shaft. If the clamping bolt is again tightened, the cam will then be securely held in its adjusted position.

By adjustment of cam iii?, any desired relationship may be established between the angular position of shaft 'I8 at which the heavy duty contacts close and the angular position at which the light duty contacts close.

When the circuit controller shaft i8 is operated by the lever 'i5 through 180 clockwise from the position shown in the drawings, then, with the cam adjustment illustrated, the heavy duty contacts will close first, and the light duty contacts will close later when the shoulder liic of cam HQ engages the cam follower iQSa.

Figs. 9 and 10 These figures illustrate the installation of a circuit controller l2 such as that shown in Figs. 6 to 8, for use in connection with a center throw lever for releasing the locks on switches at the .mal and reverse positions.

10 opposite ends of a crossover track between two main tracks. The apparatus of Figs. 9 and 10 is intended for the same general purpose as the apparatus shown and described in connection with Figs. 4 and 5.

In the arrangement of Figs. 9 and 10, the hand-throw lever 16 serves as the center throw lever for operating the lock releasing pipe line. To this end, a pin ||4 on the crank arm 7l is connected through a link H5 to the pipe line to be shifted. The circuit controller 72 is attached to a mounting plate l I6 bolted to the ties of the railway track. An electric lock 'I for the handthrow lever 'i5 is also mounted on the plate H5. The electric lock il? is provided with a latch ||3 which holds the center throw lever 'it down, and a pedal I9 by means of which the latch ||8 may be released whenever the electric lock Ill is energized.

Any suitable electric lock mechanism may be used, but I prefer to use one of the type disclosed in the copending application for Letters Patent of the United States of Herbert L. Bone, Serial No. 67,392, iiled December 27, 1948, now Patent No. 2,631,228, issued March 10, 1953, entitled Railway Traiiic Controlling Apparatus.

A pedal lock rod |20, of conventional construction, is attached to the hand-throw lever i6, and cooperates with the pedal H9 to prevent return of the pedal to its normal latching position when the hand-throw lever 16 has been moved out of the jaw of the latch. A bolt |2|4 is provided, which, in the position shown, has one end projecting under the pedal ||9 so as to prevent its downward movement in a latch releasing direction. The bolt |2| moves in a guide |22 attached to the mounting plate IIS, and its opposite end is pivotally connected to a link 23 whose opposite end is in turn pivotally connected to an eccentric pin on the hand-throw lever 7S.

When the parts are in the positions shown in the drawings, and it is desired to use the crossover track, then the switchman must rst operate the circuit controller by moving the hand-throw lever 'I9 from the position shown through 180 to its reverse position. During this movement, the heavy duty contacts in the circuit controller shunt the track circuits so that the signals on the associated main line track are set at stop. At the same time, the end of bolt |2| moves out from under pedal H9. The light duty contacts of the circuit controller i2 initiate the operation of a timing mechanism which, at the end of a predetermined period of time, energizes the electric lock lll, so that thereafter depression of the pedal |i9 releases the latch ll and allows operation of the center throw lever it* to release the locks on the track switches. After the train has passed over the crossover, it may be restored to its previous condition by throwing the two switches to their normal positions, restoring their locks by returning the hand-throw lever it to its normal position, locking that lever by returning the pedal I9 to its normal position, and then operating the hand lever 79 of the circuit controller l2 to its normal position.

It should be noted that the bolt 12| prevents restoration of the circuit controller lever 'i9 to its normal position before the pedal it has been restored to its normal position.

A pair of brackets |24 are attached to the plate l so as to receive the lever '|53 in its ncr- The brackets 12d are provided with suitable openings for the application of padlocks or other devices to prevent operation by unauthorized p-ersons, and to hold the lever down during passage of a train over the controller.

Although I have herein shown and described only two forms of circuit controllers embodying my invention, it is understood that various changes and modications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. An electric circuit controller comprising xed and movable contact structures, a support for the movable contact structure including a lember at each end of said structure, each said member having a recess slightly larger than Ythe adjacent end of the contact structure to receive said adjacent end loosely therein, and means connecting said support members for concurrent movement, said recesses permitting limited 'lateral movement of said movable structure to cornpensate for misalignment of the contact structures.

2. An electric circuit controller comprising ya stationary contact, a contact movable along a linear path to engage and disengage said stationary Contact, a rotatable shaft, a crank on said shaft, a pitman connecting said crank and said movable contact, and a spring located in the path of movement of the movable contact so as to be engaged thereby upon disengagement of said contacts, said spring being eiective to take up all lost motion in the connection of said crank, shaft and pitman.

3. An electric circuit controller comprising fixed and movable contact structures, a support for said movable contact structure, means loosely connecting said movable structure to its support to permit limited lateral movement of said one structure to compensate for misalignment between said contact structures, and a springy located in the path of movement of said movable contact structure so vas to be engaged thereby upon disengagement of said contacts, said spring being effective to prevent rattling of said movable contact structure in its loose support when the contact structures are disengaged.

ll. An electric circuit controller as in claim 3, in which said support is slidably movable along a linear path, and including a shaft, means for rotating said shaft, a crank on said shaft, and a pitman connecting said crank and said support so that rotation of said shaft causes engagement and disengagement of said contact structures, said spring being also effective to take up all lost motion in the connections of said shaft, crank and pitman.

5. An electric circuit controller comprising .a contact support, a pair of spaced contacts Xed to said support, a contact member, a contact support for said contact member including two spaced, slidably mounted members having recesses for receiving the adjacent ends of said contact member with clearance to permit limited movement oi said contact member to compensate for misalignment of the spaced contacts and the contact member, and means connecting said slidab-le members for concurrent movement to engage and disengage said contacts and contact member.

6. An electric circuit controller comprising a contact support, a pair of spaced contacts xed to said support, a contact member, a contactsup- 12 port for said contact member including two spaced, slidably mounted .members having recesses for receiving the adjacent ends of said `contact member with clearance to permit limited movement of said contactmember to compensate for misalignment of the spaced contacts and the contact member, means connecting said slidable members for concurrent movement to engage and disengage said contacts and contact member, and a spring located in the path of movement of said contact member vso as to be engaged thereby upon disengagement of the spaced contacts and the contact member to prevent rattling of said contact member in the recesses of its supporting slidable members.

7. An electric circuit controller comprising two contact supports, a contact member on one support, and a pair of spaced contacts on the other support, spaced slidably mounted members having recesses therein, projections on one of said supports receivable within said recesses with clearance to permit limited movement of said contact support to compensate for misalignment of the spaced contacts and the contact member, and means connecting said slidable members for concurrent movement to engage and disengage said spaced contacts and contact member'.

8. An electric circuit controller comprising two contact supports, a contact member on one support, and a pair of spaced contacts on the other support, spaced slidably mounted members having recesses therein, projections on one of said supports receivable within said recesses with clearance to permit limited movement of said contact support to compensate for misalignment of the spaced contacts and the contact member, means connecting said slidable members for concurrent movement to engage and disengage said spaced contacts and contact member, and a spring located in the path of movement of the contact support carried by the slidable members so as to be engaged thereby upon disengagement of the spaced contacts and the contact member to prevent rattling of said contact'support in the recesses of its supporting slidable members.

WILLIAM R. GRACEY, JR.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 903,927 Wendler Nov. 17, 1908 1,129,812 Robinson Feb. 23, 1915 1,189,015 Thomas June 27, 1916 1,229,750 Holt June 12, 1917 1,312,136 Schiffert Aug. 5, 1919 1,555,130 McCarthy Sept. 29, 1925 1,606,735 Hodgkins Nov. 16, 1926 1,687,835 Griswold Oct. 16, 1928 1,740,640 Austin Dec. 24, 1929 1,752,236 Conklin Mar. 25, 1930 1,754,446 Sachs Apr. l5, 1930 2,053,891 Beall Sept. 8, 1936 2,106,581 Unwin Jan. 25, 1938 2,178,600 Millermaster Nov. 7, 1939 2,372,594 Martin Mar. 27, 1945 2,373,636 Ulinski Apr. 10, 1945 FOREIGN PATENTS Number Country Date 107,397 Great Britain June 28, 1917 

